Aircraft often include one or more landing gear that comprise one or more wheels. Each wheel may have a brake that is operatively coupled to the wheel to slow the wheel, and hence the aircraft, during, for example, landing or a rejected takeoff. Aircraft brakes are not typically engaged voluntarily during takeoff, as brake engagement would act to impede forward motion of the aircraft. However, in the event of brake malfunction, one or more brakes may be at least partially engaged during a takeoff. Such engagement may not be enough to affect the ability of the aircraft to takeoff, and indeed, may be undetectable to the aircraft pilot and crew. In other cases, a dragging brake may prevent an aircraft from achieving takeoff speed. A pilot may elect to reject the takeoff in response to a dragging brake. A concern is that partial engagement of an aircraft brake during takeoff tends to generate heat in the brake, as the brake absorbs energy from the rotation of the wheel and thus increases in temperature. Partial engagement of an aircraft brake during takeoff may also prevent the aircraft from reaching an appropriate takeoff speed.
After take-off, landing gear may be stowed by retracting the landing gear into a wheel well of an airframe. During retraction, the wheel may or may not be rotating. Typically, the braking system may be commanded to apply braking pressure to the wheels in order to slow or stop the wheel rotation before, during, and/or after retraction into the aircraft body. A brake that is at least partially engaged at a time when no braking is commanded may be referred to as a “dragging” brake. If a brake drags during takeoff, it is not desirable to retract the wheel into the wheel well after takeoff due to the excess temperature of the brake. Retraction of a hot brake may pose a fire hazard and/or cause the tire to become too hot and fail.